Thermostatic valve for controlling the coolant temperature of an

Abstract

A thermostatic valve for controlling coolant temperature of an internal-combustion engine has a valve body with valve elements for opening and closing corresponding valve openings in response to changes in coolant temperature. In a preferred embodiment, the valve body contains an expansion agent which exerts a force on a working piston which extends out of the valve body. A reactive bearing surface on an adjustable support body is provided immediately adjacent to an end of the working piston. The distance between the reactive bearing surface and the piston and/or valve body can be adjusted to change the characteristics of the valve by changing the distance the piston must move before being restrained by the bearing surface and causing the valve body to move and the valve to open. A mechanism for restoring the piston to a desired end position within the valve body is provided to prevent possible interference with the adjustment of the valve characteristics, which might otherwise result from the piston remaining an unrestored (i.e., intermediate) extended position. In one preferred embodiment, the restoring mechanism is an elastic member, such as a spring, mounted between a stationary portion of the valve housing and stop on the piston shaft. In a second embodiment, which utilizes an electrical adjusting mechanism for adjusting the valve characteristics, the electrical circuit of the adjusting mechanism is designed such that, when the internal-combustion engine is switched off, the adjusting mechanism acts to move the piston toward the valve body.